Heart Monitor Electrode System

ABSTRACT

A bioelectric interface for monitoring, detection and transmission of detected ECG data is provided comprising a sensory system for detecting bio-physiological measurements utilizing spatially resolved potential profiles obtained from a localized cluster of sub-electrodes to form constituent sets of miniature sensor arrays. Using only a single macro-electrode, two or more sets of sub-electrode arrays are used to measure bipolar spatial gradients obtained from measured cardiac potentials. The sets of sub-electrodes containing the clusters are optimized to attain measurable gradients of diagnostic value. A minimax procedure allows bio-potential sensory acquisition through a bi-directional digital steering process, which essentially comprises monitoring, detection, selection, grouping, recording and transmission of ECG waveform characteristic data.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. Nonprovisionalapplication Ser. No. 15/974,624 filed May 8, 2018, now U.S. Pat. No.10,485,440, which is a continuation of U.S. Nonprovisional applicationSer. No. 12/012,958 filed Feb. 6, 2008, now U.S. Pat. No. 9,962,098,which is a continuation-in-part of U.S. Nonprovisional application No.12/006,907, filed Jan. 7, 2008, now abandoned, which is a continuationof U.S. Nonprovisional application Ser. No. 11/810,031, filed Jun. 4,2007, now abandoned, which claims the benefit of U.S. ProvisionalApplication No. 60/810,743, filed Jun. 2, 2006, now expired, thedisclosures of which are incorporated herein in their entireties.

COPYRIGHT AUTHORIZATION

©2008-2018 Global Cardiac Monitors, Inc. A portion of the disclosure ofthis patent document contains material which is subject to (copyright ormask work) protection. The (copyright or mask work) owner has noobjection to the facsimile reproduction by anyone of the patent documentor the patent disclosure, as it appears in the Patent and TrademarkOffice patent file or records, but otherwise reserves all (copyright ormask work) rights whatsoever.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates generally to the fields of bio-potentialsensory measurements and transmission thereof for medical diagnosticpurposes, and in a specific though non-limiting embodiment, to acomfortable, easily-affixable, portable bioelectric interface used todetect, monitor and communicate data relating to a subject patient's ECGwaveform characteristics.

Description of the Related Art

Although well-known for over a century, the full benefit of thediagnosis of electrocardiogram recordings has not been realized,primarily because it has not yet been brought to the state of fullclinical exploitation such technology deserves. Possible reasons forthis shortfall include institutional resistance to sophisticated newelectronics capable of subsuming the functions of many previouslyexistent devices; misperceptions within the medical community regardingthe possible uses of such systems when the technology is fully⋅matured;the fact that few, if any, prototypical devices have been reduced topractice for experimentation, etc.

The net result of such reluctances has been to restrict theproliferation and effectiveness of ECG monitoring systems to clinics,hospitals, and emergency rooms. More effective functionality, such asauto-detection, wireless transmission, and ultimate ease of usage, hasheretofore been unknown.

For example, the state of the art presently is to affix upon a subjectan electrocardiogram recording system based on measurement of thepotential difference from at least a pair of electrodes thatare⋅distinctly separated, and which connect with leads that terminate inthe amplification stage. Examples of standard lead systems include thesignal averaging x, y, z Frank set, and the 10 electrode averagingsystems derived from the well-known, clinically standard 12 lead system.In virtually all cases, the electrodes are connected with wire leads toeither an amplifier or a recording device.

It is problematic, however, that when affixing subjects with thestandard 12-lead monitoring system, subjects must be affixed with all ofthe electrodes disposed in a proper anatomical position. Failure to soequip the subject results in either failure or poor reporting of theapparent ECG waveform.

Even when proper anatomical disposition is achieved, orientation andgrouping of disjunctive constituent clusters is adversely influenced bythe orientation of the myocardium muscle fibers with respect to theaspect of the cumulatively resulting solid angle obtained from a set ofthe electrodes. With respect to the sequence of activation, the spreadof the activation stimulus moves from endocrinal sites on out to thetransmural space. This space is heavily affected by the anisotrophicproperties of the ventricular muscle.

It is intuitive that excitation or the wavefront will spread morerapidly along the long axes of the cardiac cell than in the transversedirection. In ventricular walls, fibers are oriented roughly parallel toboth endocardial and epicardial surfaces, however there are sometransverse connections between cells, therefore the spread from oneendocardial point may be viewed as oblique. This means there is apredominant axial spread along the length of the fiber with a lesserdegree of spread or activation along the transverse in the perpendiculardirection. The cumulative effects of the resulting cardiac fieldmanifest into corresponding deviations in the measured cumulativewaveform. In short, measuring errors translate into analytical errors,which are then compounded during the amplification and recordingprocess. The net result is that a testing protocol designed to beexacting and precise is not, much to the detriment of cardiac patientsand their attending physicians.

It is also problematic that the wire leads associated with theelectrodes more or less requires that the subject be confined andremains relatively still, and the lack of reliable remote reportingcapability ensures that the subject must remain on-site during cardiointerrogation. Consequently, benefits that could otherwise have beenderived from the remote acquisition, transmission, and interpretation ofwaveform characteristics are not realized.

Several derivative electrode arrangements (for example, large patches)have been proposed as an alternative to the clinical standard. However,the basic challenge remains that such electrodes must be contiguous andsufficiently spatially separated. To avoid that fundamental necessity,prior arts have attempted and demonstrated embedded wires disposed in alamination in various arrangements. However, the obstacle remains thatthese electrodes are contained within a relatively larger patch in whichelectrodes still have to be connected by wires disposed at relativelylarge spatial distances.

Accordingly, the prior art is deficient in achieving a clinically usefuldiagnostic potential gradient from a single electrode comprising aplurality of sub-clusters subtending and delimiting an area of no morethan a few of inches or less.

Logical protocols, functional depictions, and satisfactory methodologies(i.e., decision rules) for constructing waveforms obtained from two orthree sets of selected sub-clusters disposed in specific orientations,whether contiguous or disjointed, and grouping strategies fordetermining optimum signal acquisition, are also conspicuously absent.

SUMMARY OF THE INVENTION

A method of obtaining local gradient values from a bio-potential sourcefor the purpose of cardiac monitoring is provided, wherein the methodincludes parsing of data obtained from clusters of sub-electrodesdisposed on a single macro electrode.

An on-board electrode signal acquisition system is also provided,wherein the system includes filtering and processing capabilities, andwherein an associated dynamic range is set to a sufficiently broad rangeas to accommodate excursions intended to define baseline boundaries.

An ECG system in which a macro electrode having a plurality ofsub-electrodes is combined with leads combined with a plurality ofadditional macro electrodes is also provided, wherein one or more of theadditional macro electrodes further include a plurality ofsub-electrodes.

A method of networking an ECG monitoring system which includes a masterelectrode is also provided, wherein remote interrogation of themonitoring system is carried out using voice data digital signalpackaging.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an overhead and side view of a heart monitor electrodestructure.

FIG. 2 depicts overhead, underneath, and cutaway views of the presentlyclaimed heart monitor.

FIG. 3 illustrates examples of the remote transmission, monitoring andinterrogation aspects of the presently claimed heart monitoring system.

DETAILED DESCRIPTION OF THE INVENTION

1. As mentioned, rudimentary patches and electrode clusters for clinicalelectrocardiography have been proposed and described in the prior art.However, the prior art has not understood and correctly manipulatedseveral major principals in biopotential sensing paramount forsensitivity, spatial resolution, and correct orientation of electrodeswithin clusters comprising sub-electrodes confined to a relatively smallzone.

These principals are:

(A) A single electrode sensor array used to spatially resolve highlylocalized gradient profiles from a cluster of sub-electrodes to formconstituent sets comprising subelectrodes under a specific decisionrule. Such clusters will provide a minimum of two constituent, thoughnot necessarily contiguous, sets obtained from members of the cluster todiscern a measurable potential difference. See FIGS. 1 and 2.

(B) A so-called “minimax” procedure that allows for bio-potentialsensory acquisition through a digital steering process, in whichmonitoring, selecting, grouping, recording and transmission options arederived from permutations of a plurality of sub-electrodes confined tothe size of the typical ECG electrode.

(C) Potential contributions from all possible permutations of thecluster of subelectrodes combined and parsed into two or three macroconstituent sets.

(D) A rotational invariance property resulting from the virtual steeringof subelectrodes within cluster(s) to obtain measurable potentialdifference.

(E) A battery structure that provides power to both the body of theelectrode and its sensor array. Power is also required for whateverextent of processing and transmission functions are carried out onboardthe device, and to transmit raw data for processing to an associated,proximately disposed processor device, for example, remote processorworn by the subject in a harness.

(F) A wireless topology network model, wherein a remote monitor caninterrogate the portable electrode unit. See FIG. 3.

(G) A distinct single electrode that is autonomous and lead-free,thereby achieving single electrode results with onboard DSP inassociation with arrhythmia detection capabilities, source encoding, andpassive and active wireless transmission.

Consequently, the claimed invention essentially includes a dataacquisition system capable of acquiring ECG data in association with auseful memory and a logical analytic protocol. Further aspects comprisea full duplex transmitter and receiver disposed, either onboard or inclose physical proximity therewith (for example, contained within anassociated portable harness or the like) in electrical communicationwith a structurally integral unit comprising a single electrode and abattery on an area spanning less than or approximately the same area asa typical electrode used in the presently known 12 lead clinical system.

2. The aforementioned sub-electrode data acquisition system compriseselements of:

(A) a bio-potential interface having a sensor array comprising aplurality of sub-electrode clusters integrated into a single system usedto obtain gradient indicators obtained from highly localized potentialdifferences; (B) a plurality of sub-electrode sets spatially parsed andin accord with a minimax method adapted to each individual subjectpatient in order to align sub-electrodes constellations in a manner soas to attain a measurable divergence between and amongst cardiac fieldforce vectors; (C) an accumulated history of each patient'selectrophysiological activity for purposes of arrhythmia detection andmonitoring; and (D) a wireless network methodology used to maintainconnectivity and assist with remote physician interrogation duringcritical sessions:

3. For clarity, it will probably be useful to note the followingdefinitions employed throughout the balance of this disclosure:

(A) As used herein, the term “constituent sets” refer to either the 2set model or the 3 set model of sub-electrodes, which, in the three setmodel constitute an exploring set, a reference set, and a ground set. Inthe two set model, the reference set is not present.

(B) The term “model” refers to either of 2 or 3 set clusters.

(C) The term “critical session” refers to a phase wherein an event ofcardiac significance has been detected and stored, and is eitherawaiting transmission or is already in the process of being transmittedfor analysis. Regarding “awaiting transmission,” it is possible that abrief delay could be incurred due to, for example, a wireless networkdelay, etc.

(D) The term “measurable” refers to any detectable⋅potential derivedfrom any diagnostic value obtained from waveform excursions.

(E) The term “enclosure model” refers to a structural embodiment whereina battery is either or partially enclosed.

4. One aspect of the invention utilizes temporal and spatial-resolveddetection of bio-physiological potential to obtain discernible waveformsfrom highly localized clusters of dry, gel, or suction cup electrodesfrom a body surface or from organs for diagnostic purposes. A relateddiagnostic procedure comprises a method in which the utility of aminimum of a single electrode is used to detect, as an example of oneembodiment, the cardiac electrical disturbance. Drawing upon andrecognizing the fundamentals of electrochemical processes thatprecipitate the various phases of action potential during the cardiaccycle, as well as the spatial and temporal correlations of associatedindividual and epidemiological data, reasonable inferences can be madeas to the spatial and temporal gradient divergence and its spectra:Selection and formation of particular constellations are dictated bythose sub-electrodes disposed coincident and subjacent to thesub-potential contours of high divergence during the cardiac cycle,thereby contributing the most to a measurable differential waveform.

Cardiac potentials sensed on body surfaces emanate as the result of acardiac electric field interacting with metallic or gel electrodesaffixed on the body surface. Thus, an electrode is essentially atransducer for transforming charges in electrolytes, i.e., anions andcations, into electrons (and vice versa) in metals in electroniccircuits. With the aid of electrochemical gradients in the intra- andextra-cellular spaces, anions and cations are moved with the assistanceof what is essentially a perpetual sodium pump that energizes the cell,thereby causing the action potential to travel through the conductionsystem of the myocardium. Conduction and displacement of capacitivecurrents flow across from cell to cell, entering and exiting through thecell membranes, in order to eventually activate and contract theventricle pump. Electromagnetic fields from the activated myocardiumproject outwardly where subtending electrodes intercept that can besensed as bio-potential on the body surface and then recorded.

The fundamental requirement of attaining a discernible gradient from asingle electrode comprising clusters of N number of sub-electrodes in ahighly localized potential warrants transition to the presently claimedtechnology.

Joint adaptive capabilities at the circuit level, e.g., joined elementssuch as capacitors and resistors, as well as digital processing permitiso-potential lines or contours to dictate the specific orientation ofthe sub-electrodes, and the subtending of clusters of sub-electrodes, toattain the said desired diagnostic gradient. The clusters orconstellations of sub-electrodes, and of the resulting sets of such,need not be contiguous or uniform relative to one another, nor shouldthey be exhaustive of all of the N sub-electrodes coincident tosubjacent fibers to reveal the nature and extent of potentialvariability during the cardiac cycle.

5. Decision Rules

In one embodiment, all sub-electrodes present in the system terminateinto a logical device, such as an addressable multiplexer, and thesignals obtained from the electrodes are processed in accord withinstructions from a microprocessor, digital signal processor (DSP), orany other suitable digital processor. Various sub-electrodes arecombined into prospective sets to form the minimum necessary 2 or 3constituent sets described above. These sets represent the potentialpoints to obtain spatial/temporal waveform excursions, and arereflective of the cardiac signal that is preferably least noisy. Thesets of clusters of sub-electrodes produce an effective orientation ofhighly localized bipolar arrangements that are then parsed in such amanner so as to discern or maximize the signal gradient associated withthe least interference noise.

The selection of the 2 or 3 set clusters of sub-electrodes need not bedependent upon a contiguous grouping of clusters, though suchdisposition certainly can provide a maximum potential gradient with somesense of optimality if necessary. One possible optimality rule would beto combine sub-electrodes to contribute to a stable gradient, preferablyof some visually desired display that is free or indiscernibly tolerableof AC interference, for example. Disposed on-board the master electrodemodule, or at minimum in electrical communication therewith, is a set ofamplifiers and an addressable multiplexer used to communicate dataregarding each all of the potential permutations obtained from thesub-electrodes to a signal processor or the like. The set of amplifiersis also used to assist in the selection of localized candidate clustersfrom amongst the possible spectrum of sub-electrode candidate clusters.The master electrode module can also be used as a hub for other masterelectrodes, thereby effectively forming a system of such masterelectrodes analogous to the standard electrode arrangements alreadyknown. In this case, each of the master electrodes, which would take theplace of one of the simple, basic electrodes presently used in thestandard system, would provide a significantly more accuraterepresentation of actual cardio activity than would the standardclinical system.

The orientation selection process may exhaustively consider all possiblecombinations of sub-electrodes, or may instead continue only until adesired bipolar potential is attained. In some embodiments, the primarycriterion is that maximum number of ECG excursions that both fall intothe ECG band and are void of AC interference. A ground electrode may benecessary in certain embodiments, but in others only two electrode sets,each of which contain at least one sub-electrode, will suffice forobtaining the desired diagnostic EGG signal.

The method herein described thus obtains electro-potential data fromeach of the leads of the heart monitor, determines which leads have themaximum potential difference, and uses that maximum potential differenceas the heart monitoring data, using maximum potential for monitoringdata enhances the data readability and reliability.

In short, the minimax algorithm isolates and considers a minimum of twoconstituent sets selected from members of the cluster in order todiscern measurable potential differences. Potential from all possiblepermutations of the cluster constituting at least two sets ofsub-electrodes are combined, and then parsed into two or three macroconstituent sets or constellations. Each set can have a minimum of onesub-electrode. A distinct lead-free single electrode that isrotationally invariant results with onboard DSP for arrhythmiadetection, source encoding, and passive and active wirelesstransmission.

This lead-free, bio-physiological adapter allows for utmost clinicaloperational freedom and dramatically obviates the need for leads of anylength that invariably encumber the acquisition and performance of ECGrecordings as presently performed.

6. Conclusion

The foregoing specification is provided for illustrative purposes only,and is not intended to describe all possible aspects of the presentinvention. Moreover, while the invention has been shown and described indetail with respect to several exemplary embodiments, those of ordinaryskill in the pertinent arts will appreciate that minor changes to thedescription, and various other modifications, omissions and additionsmay also be made without departing from either the spirit or scopethereof.

I claim:
 1. A non-invasive method of obtaining local gradient valuesfrom a bio-potential source for the purpose of biophysiological signalmonitoring by affixing a lead-free, autonomous single macro electrode,without regard to anatomical orientation, to a body surface of a subjectto be monitored, the macro electrode comprising a group of N number ofsub-electrodes, namely, two or more sub-electrodes arranged in a highlylocalized constellation capable of detecting highly localized, closelyspaced biophysiological electrical potential gradients between two ormore constituent sets of the sub-electrodes, each set of sub-electrodescomprising at least one distinct sub-electrode of the two or moresub-electrodes; acquiring the biophysiological signal from two or moreof the sub-electrodes within the constellation; parsing data obtainedfrom all sub-electrodes disposed upon the single macro electrode with amicroprocessor disposed in communication therewith; and determining withsaid microprocessor a set of sub-electrodes that contributed to themaximum local gradient according to the anatomical orientation of themacro electrode on the body surface of the subject; and wirelesslytransmitting the determined maximum local gradient, wherein the macroelectrode is affixed to the body surface of the subject without regardto rotational orientation of the macro electrode.
 2. The method of claim1 further comprising the step of remote interrogation of the macroelectrode carried out using voice data digital signal packaging.
 3. Themethod of claim 2, wherein said remote interrogation of the macroelectrode discerns data relating to biophysiological phenomena occurringin muscle tissue.
 4. The method of claim 1, wherein the biophysiologicalsignal originates from the subject's heart.
 5. The method of claim 1further comprising the steps of parsing the data from all of thesub-electrodes; determining which of the sub-electrodes, either alone orin combination with another sub-electrode or other sub-electrodes or acombination of other sub-electrodes, provide a maximum gradient valuewhen contrasted against said another sub-electrode or said othersub-electrodes or said combination of sub-electrodes; and using the sodetermined maximum gradient value for the purpose of thebiophysiological signal monitoring.
 6. The method of claim 5 wherein thesteps of parsing are conducted using a minimax procedure adapted to eachindividual subject to be monitored in order to align sub-electrodes in amanner so as to attain a measurable divergence between and amongstbiophysiological signals.
 7. The method of claim 5 wherein the steps ofparsing are conducted using a minimax procedure that allows forbio-potential sensory acquisition through a digital steering process, inwhich monitoring, selecting, grouping, recording and transmissionoptions are derived from permutations of a plurality of thesub-electrodes.
 8. The method of claim 5 wherein the sub-electrodessubtend and delimit an area of no more than a few of inches or less. 9.The method of claim 5 wherein the steps of parsing occur on a temporaland spatial basis.
 10. A system for obtaining biophysiological sensorymeasurements from a subject, in which a lead-free, autonomous singlemacro electrode having a plurality of sub-electrodes arranged in ahighly localized constellation capable of detecting highly localized,closely spaced biophysiological electrical potential gradients betweentwo or more constituent sets of the sub-electrodes, each set ofsub-electrodes comprising at least one distinct sub-electrode of the twoor more sub-electrodes, is combined with leads combined with a pluralityof additional macro electrodes, one or more of which also furthercomprise a plurality of sub-electrodes, the macro electrodes beingaffixed, without regard to anatomical orientation, to a body surface ofthe subject, the system further comprising a microprocessor disposed incommunication therewith, the system capable of acquiring thebiophysiological signal from two or more of the sub-electrodes withinthe constellation, parsing data obtained from all sub-electrodesdisposed upon the single macro electrode with said microprocessor, anddetermining, with said microprocessor, a set of sub-electrodes thatcontributed to the maximum local gradient according to the anatomicalorientation of the macro electrode on the body surface of the subject;wherein the macro electrode is affixed to the body surface of thesubject without regard to rotational orientation of the macro electrode,and wherein said system is capable of wirelessly transmitting thedetermined maximum local gradient.
 11. The system of claim 10 furthercomprising an on-board electrode signal acquisition system, wherein saidsignal acquisition system comprises filtering and processingcapabilities, and wherein an associated dynamic range is set to asufficiently broad range as to accommodate excursions intended to definebaseline boundaries.
 12. The system of claim 10, wherein saidmicroprocessor further comprises an adaptive algorithm comprising logicand a decision rule useful for enabling adjustment of parameters foracquiring bio-potential measurements.
 13. The system of claim 10,further comprising a source encoder used to reduce the size of a digitalrepresentation of measured bio-potential.
 14. The system of claim 10,further comprising a battery disposed within an enclosure in such amanner said battery can be extricated out of, and then a replacementbattery wedged back into said enclosure.
 15. The system of claim 10,wherein the system measures biophysiological sensory signals originatingfrom the subject's heart.